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Old Feb 12, 2012, 01:19 PM
220 221 Whatever it takes
captdave221's Avatar
USA, IL, Belleville
Joined Dec 2009
276 Posts
Umx spitfire speed

The one(s) I saw fly at E-Fest yesterday looked faster than the GeeBee's they were flying. Close up it looks awesome and I can't wait to get one. $99 looks like a great deal especially compared to other micro planes.
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Old Feb 12, 2012, 01:42 PM
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DaveG's Avatar
Houston, TX, US
Joined Jun 2000
1,652 Posts
Thanks for the E-Fest sighting report. It sure looks nice in the photos.
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Old Feb 12, 2012, 02:17 PM
LiPo-Sucker & Airframe EMT
pugsam's Avatar
Charlottesville, Virginia, USA
Joined Aug 2010
3,529 Posts
Quote:
Originally Posted by captdave221 View Post
The one(s) I saw fly at E-Fest yesterday looked faster than the GeeBee's they were flying. Close up it looks awesome and I can't wait to get one. $99 looks like a great deal especially compared to other micro planes.
Any photos -- or vids???

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Old Feb 12, 2012, 03:17 PM
The Sweet Aroma of 92 Octane
electricrc68's Avatar
United States, PA, Downingtown
Joined May 2011
4,405 Posts
Quote:
Originally Posted by airpower View Post
Electric, youll know when you get one.
A geared brushed motor sounds/feels dirty to me.
So why do i keep buying them
actually i do have 2 brushed planes; ember 2 and t-28. although i don't really see a problem with their noise...maybe i will after i get a brushless one.
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Old Feb 12, 2012, 03:41 PM
Have fun
airpower's Avatar
Joined May 2007
6,088 Posts
That's what i meant, sorry, you know how much you prefer brushless when you get a brushless. And its clean and no dirty gearbox and brushless cogging and OHHHH i swear some features on planes turn me on. My girlfriend knows this, so she put aviation art up in her room
There are planes that i dont mind brushed power, like the mossie, and most 3 channels. It makes their size, cost, easy of use possible.
I know many of us are dissapointed by it being brushed, but i'll say this,
If you liked the corsair(after furthering cg, computer radio, etc), you'll like this. Of course it'll fly better,but it's the same demographic/niche.
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Old Feb 12, 2012, 03:59 PM
The Sweet Aroma of 92 Octane
electricrc68's Avatar
United States, PA, Downingtown
Joined May 2011
4,405 Posts
Quote:
Originally Posted by airpower View Post
That's what i meant, sorry, you know how much you prefer brushless when you get a brushless. And its clean and no dirty gearbox and brushless cogging and OHHHH i swear some features on planes turn me on. My girlfriend knows this, so she put aviation art up in her room
There are planes that i dont mind brushed power, like the mossie, and most 3 channels. It makes their size, cost, easy of use possible.
I know many of us are dissapointed by it being brushed, but i'll say this,
If you liked the corsair(after furthering cg, computer radio, etc), you'll like this. Of course it'll fly better,but it's the same demographic/niche.
yeah the only brushless rc i have used so far is a brushless rc car. after you mention it, my ember 2 does seem to have some dirt on its gears.
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Old Feb 12, 2012, 04:22 PM
LSF 004 - AMA 5055
bobandris's Avatar
Saratoga, CA USA
Joined Dec 2000
587 Posts
Scale Speed

Just have to jump in on this scale speed discussion. The guideline
i use is: I want the model to travel it's own fuselage length in the same amount of time it takes the full-size to travel it's own full-size fuselage length.

Bob
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Old Feb 12, 2012, 04:37 PM
Gopher huntin' stick jockey
turboparker's Avatar
East Bethel, MN USA
Joined Jul 2009
11,660 Posts
Quote:
Originally Posted by bobandris View Post
Just have to jump in on this scale speed discussion. The guideline
i use is: I want the model to travel it's own fuselage length in the same amount of time it takes the full-size to travel it's own full-size fuselage length.

Bob
Bob,

To appear that it is traveling at the same speed as its full-scale counterpart, a model must traverse the observers field-of-view in the same amount of time as the full-scale - when the model is at the distance where it's apparent size is the same as the full-scale. It is a fact that scale speed = the square of the scale factor. The formula is used in movies all the time when they're using scale models. It is also the rule that's used for judging scale speed at RC competitions.

I suggest that you read this article: Understanding Scale Speed - by Bob Boucher.

Joel
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Old Feb 12, 2012, 11:16 PM
Your customer
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Berkley, MI
Joined Dec 2009
1,384 Posts
whoops wrong thread....
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Old Feb 12, 2012, 11:46 PM
Registered User
United States, CA, Ridgecrest
Joined Dec 2011
36 Posts
TurboParker: I understand your position and our difference is only semantic. Boucher's analysis is correct, but he's talking about something a bit different than I. He's including scaling time, which movies do by shooting with high speed cameras to slow the action and make scale models respond with apparent full scale physics. Notice he mentions scale time. When we're at the field watching our own planes in real time, we can't change time to slow our planes down. To get the plane moving at the same apparent rate as a real one it has to transit it's own length in the same delta time, in real time, as the real one, so scale speed is directly proportional to scale factor.

However, this is nearly impossible because the aerophysics cause small models to have to move much faster to stay airborne. The weight goes as scale cubed, the wing area as scale squared, so the wing loading goes as scale. The stall speed is proportional to the square root of the wing loading so it decreases as the square root of scale factor, but that's in real mph. The scale speed is real speed divided by scale factor, so it goes UP as the inverse of the square root of the scale factor and model planes have to takeoff and land much faster than scale. Maybe the square root factor is included in competitions to acknowledge that limitation, i.e. performance and loops etc. are judged in "scale time" which is faster than real time by the square root of the scale factor.

The discrepancy is purely semantic: Boucher is scaling time; some of us want scale speed in real time (but we're not likely to get it). At least the PZ micro Spit is helped by its very low wing loading (est. 16 gm/dm^2) for an estimated stall speed of about 10 real mph.
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Old Feb 13, 2012, 12:36 AM
Erich Parkmann
United States, CA, Sacramento
Joined Jan 2012
114 Posts
Quote:
Originally Posted by airpower View Post
My girlfriend knows this, so she put aviation art up in her room
Cool story bro.
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Old Feb 13, 2012, 03:37 AM
Kit Manufacturer
coreman's Avatar
United States, MA, Southbridge
Joined Feb 2010
3,496 Posts
Quote:
Originally Posted by ArticWolf View Post
Cool story bro.
yeah, the "let me show you my etchings" lives on
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Old Feb 14, 2012, 12:16 PM
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United States, OH, Cincinnati
Joined Sep 2010
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Neat
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Old Feb 14, 2012, 01:36 PM
Gopher huntin' stick jockey
turboparker's Avatar
East Bethel, MN USA
Joined Jul 2009
11,660 Posts
Quote:
Originally Posted by TP715 View Post
TurboParker: I understand your position and our difference is only semantic. Boucher's analysis is correct, but he's talking about something a bit different than I. He's including scaling time, which movies do by shooting with high speed cameras to slow the action and make scale models respond with apparent full scale physics. Notice he mentions scale time. When we're at the field watching our own planes in real time, we can't change time to slow our planes down. To get the plane moving at the same apparent rate as a real one it has to transit it's own length in the same delta time, in real time, as the real one, so scale speed is directly proportional to scale factor.

However, this is nearly impossible because the aerophysics cause small models to have to move much faster to stay airborne. The weight goes as scale cubed, the wing area as scale squared, so the wing loading goes as scale. The stall speed is proportional to the square root of the wing loading so it decreases as the square root of scale factor, but that's in real mph. The scale speed is real speed divided by scale factor, so it goes UP as the inverse of the square root of the scale factor and model planes have to takeoff and land much faster than scale. Maybe the square root factor is included in competitions to acknowledge that limitation, i.e. performance and loops etc. are judged in "scale time" which is faster than real time by the square root of the scale factor.

The discrepancy is purely semantic: Boucher is scaling time; some of us want scale speed in real time (but we're not likely to get it). At least the PZ micro Spit is helped by its very low wing loading (est. 16 gm/dm^2) for an estimated stall speed of about 10 real mph.
In the article, Boucher specifically discussed RC aircraft scale speed - not moviemaking. Furthermore, he is addressing the aspects of scale speed independently, and hie final analysis is all-encompassing. Scale-appearing speed = the square of the scale factor. Any other relationship will not appear to be scale. Believe what you wish, but this is the accepted method of determining scale speed.

Joel
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Old Feb 14, 2012, 01:39 PM
R.C. Aviation Fanatic
Razors edge 29's Avatar
Canada
Joined Aug 2009
20,581 Posts
I hope these new bricks can go brushless

also, is there 2 servos on the brick like the AR6400(L) or all separate like the newer 2S bricks?
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